感染白粉菌玫瑰对甜菜夜蛾幼虫取食与发育的影响

Influence of Sphaerotheca pannsa Infested Rosa rugosa on Feeding and Larva Development of Laphygma exigua

用感染白粉病的玫瑰叶片饲养甜菜夜蛾3龄幼虫,测量取食量,观察生长发育情况。结果表明:无选择试验中,甜菜夜蛾从3龄幼虫至化蛹,对健康叶片的取食量达1 125.6 mm2/虫,而对感病叶片的取食量只有764.0 mm2/虫;在有选择试验中,甜菜夜蛾总偏好取食健康叶片,从3龄幼虫至化蛹对健康叶片的取食量达979.7 mm2/虫,而对感病叶片的取食量只有165.7 mm2/虫。感病玫瑰叶片对甜菜夜蛾生长发育的影响主要表现在:进入预蛹期时间延长,死亡率高,化蛹率低,蛹质量明显降低;表明甜菜夜蛾取食感染白粉菌的玫瑰叶片后生长发育和取食量均受到明显影响。

Leaves of Rosa rugosa infested by Sphaerotheca pannsa disease were used to feed 3^rd instar larvae of Laphygma exigua and the feeding quantity and larva development were measured and recorded to compare with the control. The results indicated that in the no-choice test, during the process from the 3^rd instar larvae to the pupa stage, the feeding quantity of the Laphygma exigua larvae fed with the healthy leaves of 9 was 1 125.6 mm^2 per larva, whereas the feeding quantity of the Laphygma exigua larvae fed with the infested leaves of Rosa rugosa was averagely about 764mm^2 per larva. In the dual choice test, the healthy and infested leaves were offered simultaneously, and the larvae preferred to feed on the healthy leaves. Each larva averagely took about 979.68mm^2 healthy leaves from the 3^rd instar larva stage to pupa stage. However, each larva meanly took only 165.72mm^2 infested leaves during the same period of time. It was observed that the infested Rosa rugosa leaves would delay the development time of Laphygma exigua from instar larva to pupa stage, increase the mortality rate, decrease the pupation rate and reduce the pupa weight. It was showed that the growth, development and feeding quantity of Laphygma exigua were all significantly influenced by taking the Sphaerotheca pannsa disease infested Rosa rugosa.